This invention relates to containers which can be opened and closed repeatedly and continue to achieve a good seal between the cap and the container.
A good seal is especially desirable if the substance in the container needs protection from the outside environment, such as a powdered beverage mix which can cake with continuous exposure to very humid air. It is desirable to be able to manufacture an inexpensive cap and container assembly, which can be used for initial packaging of the product prior to sale, and which can continue to be opened and resealed by the purchaser of the product.
Some existing containers are too expensive for the packaging of inexpensive products, difficult to reseal effectively, or simply cannot be resealed effectively.
The present invention is a cap and container assembly which can repeatedly achieve a good seal. Annular protrusions depend from a curved cap top, and the top of the container neck slants out, then in, and then out as the neck extends down from the mouth of the container. As the cap is secured to the container, the protrusions engage exterior and interior surfaces of the neck, and the curved cap top and the upper part of the neck flex to facilitate forming a good seal. Stopping surfaces form a positive stop to lower engagement of the cap with respect to the container beyond a certain point, limiting the temporary deformation of shape caused by the flexing. The dimensions of the protrusions and the neck surfaces are matched to achieve a good seal at the lowest engagement of the cap with respect to the container permitted by the stopping surfaces.
The features of the present invention which are believed to be novel are set forth below with particularity in the claims. The invention, together with further advantages thereof, may be understood by reference to the following description in conjunction with the accompanying figures, which illustrate some embodiments of the invention.